Broadcast data receiver system

ABSTRACT

A broadcast data receiver system is provided and a method of operating the system. The system includes a first broadcast data receiver (BDR) ( 2 ) located at a first location, typically in a premises. The BDR ( 2 ) receives video, audio and/or auxiliary digital data broadcast from a remote location via cable, satellite or terrestrial means. The BDR processes the data and displays the processed data on a display screen ( 10 ) and/or audio data via speakers connected thereto. At least a second broadcast data receiver ( 8 ) is provided at least a second location typically in the same premises. One of the first and second BDRs ( 2, 8 ) is made functional by a signal received from the other of the first and second BDRs, via a telecommunications line ( 4 ) provided in the premises and connecting the first and at least second BDRs together, thereby ensuring that both BDRs are connected before operation of the two BDRs can be achieved.

RELATES BACK

This application is the National Phase of PCT Application Ser. No.GB01/03373 filed 26 Jul. 2001 which claims priority from British PatentApplication No. 0103830.6 filed 16 Feb. 2001.

BACKGROUND OF THE INVENTION

The present invention relates to a broadcast data receiver systemcomprising a first and at least a second broadcast data receiver incommunication therewith.

Broadcast data receivers (BDR's) are used in television systems toreceive digital data broadcast from a broadcaster at a remote locationvia cable, satellite and/or terrestrial means and process the digitaldata for display on a display screen or sounding via speakers connectedthereto. The number of program channels available via digital televisionsystems is far greater than the number of programs available usinganalogue systems and, as such, digital television is becomingincreasingly popular. As a result, it is becoming common for users tohave two or more BDR's in their homes, for use with two or moretelevision display screens. To encourage user's to provide a BDR witheach of the televisions in the premises of the home, some broadcastersare providing a free or discounted second BDR to existing customers.

The second BDR is typically a complete receiver unit, similar oridentical to the first BDR and capable of receiving data from abroadcaster, processing the data for display, having a smartcard and/orthe like. However, a problem facing broadcasters who provide two or moreBDR's to a customer is that the two BDR's may be used in differentpremises, thereby allowing a user to give or sell one of the BDR's to afriend, neighbour or similar. This reduces the broadcaster's revenue dueto lost subscriptions and is therefore undesirable.

One method being used by broadcasters to try and overcome this problemis to provide an RS232 data connection (standard external modem) betweenthe two BDR's to ensure that they are being used in conjunction witheach other in the same premises. However, a problem with this method isthat it requires adapters and additional cabling to be fitted to theBDRs which is expensive and is therefore less likely to persuade acustomer to have more than one BDR. In addition, it is not entirelyfoolproof as an extended connection can be provided between the twoBDR's to allow the BDR's to be used in different premises, thereby stillresulting in the initial problem faced by the broadcasters.

SUMMARY OF THE INVENTION

It is therefore an aim of the present invention to provide a systemwherein the broadcaster can ensure that two or more of their BDR's arebeing used in the same customer premises/at the same customers address.

According to a first aspect of the present invention there is provided abroadcast data receiver system comprising a first broadcast datareceiver (BDR) located at a first location, said BDR receiving video,audio and/or auxiliary digital data broadcast from a remote location viacable, satellite or terrestrial means, said BDR processing said data anddisplaying said processed data on a display screen and/or audio data viaspeakers connected thereto, and at least a second BDR provided at atleast a second location, characterised in that one of said first andsecond BDRs is made functional by a signal received from the other ofsaid first and second BDRs via communication means connecting the firstand at least second BDRs together.

Preferably the first and at least second BDR are provided in the samepremises.

Preferably the communication means is a telecommunications line.

Preferably one of the first and at least second BDR has to be enabled bythe other(s) of the first and at least second BDRs in order to performone or more functions, such as receiving data, processing data,displaying data and/or the like.

Preferably the telephone line is a functional Public Switched TelephoneNetwork (PSTN) connection.

Preferably the first and at least second BDR are connected via thetelephone line in parallel.

Preferably the at least one other BDR is provided with a timer such thatthe BDR will only function for a limited period of time upon activationunless the timer is reset.

Preferably resetting of the timer is provided by the input of anauthorisation code into the BDR.

Preferably the authorisation code is communicated to at least one of theBDRs from the broadcast (“head end”) transmitter.

Further preferably the authorisation code is communicated to the otherBDRs from the first BDR via the telephone line within the premises. Theauthorisation code can be regularly changed at the head end of the BDRsoftware if required.

In one embodiment, communication between the first and at least oneother BDR is allowed when both BDR's are enabled by the broadcast “headend”.

Further preferably the broadcast head end allows communication for apre-determined period of time.

Preferably a communication sequence is initiated by the second BDR onreceipt of a message from the broadcast head end transmitter.

It can be seen that without regular communication between the first andat least second BDR's, the at least second BDR will not function afterthe period of time set by the timer has expired.

According to a second aspect of the present invention there is provideda method of operating a broadcast data system, said system comprising afirst BDR located at a first location, said BDR receiving video, audioand/or auxiliary digital data broadcast from a remote location, and atleast a second BDR located at at least a second location, said first andat least second BDR connected together via a telecommunications line,characterised in that said method includes the steps of the first BDRmonitoring the line status, the at least second BDR taking thetelecommunications line off the hook when operation of the at leastsecond BDR is required, said first BDR detecting a change in line statusand then initiating communication between said first BDR and said atleast second BDR, thereby allowing the at least second BDR to becomeoperational.

Preferably the first and at least second BDR are provided in the samepremises.

Preferably the first BDR communicates an authorisation signal to thesecond BDR to the second BDR to operate.

Preferably the telephone line status is monitored by monitoring the linevoltage therein.

An advantage of the present invention is that a telephone line typicallyalready in the premises can be used to implement communication betweenthe first and at least second BDR, such that there is no requirement forextra adaptors and cabling. The present invention therefore provides aninexpensive solution which is secure and robust. The modulation methodused to transfer data between the two BDR's is a standard modulationtechnique, such as Frequency Shift Keying (FSK) or line currentmodulation. This allows the existing BDR modems to be used withoutmodification and to prevent adverse disruption of the telephone networkor exchange.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the broadcast data receiver systemaccording to the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will now be described withreference to the accompanying FIG. 1 wherein:

It has become an increasing problem that where broadcasters provide twoor more BDR's to customers, the two BDRs may be used in differentpremises, thereby allowing a user to give or sell one of the BDR's to athird party but only a single subscription be paid to the broadcaster.This is a problem which the present invention overcomes.

A first BDR 2 is normally connected to a user's live telephone line 4via a local wall socket 6. In accordance with the present invention, asecond BDR 8 is also connected to the same telephone line in parallelvia a standard extension socket point within the user's premises.

The first and second BDRs are typically located at different locationswithin the user's premises and both BDRs are connected to televisiondisplay screens 10 and 12 respectively.

The first BDR 2 monitors the telephone line status using a conventionalline voltage measurement method. For example, the voltage on thetelephone line 4 can be measured every 300 mS using a capacitor chargedischarge technique.

The broadcast “head end” initiates a communication sequence between thefirst BDR 2 and the second BDR 8 by transmitting a unique secure message(EMM) within the datastream to both BDRs simultaneously.

One receipt of this message, the second BDR 8 attempts to communicatewith the first BDR 2, which is also now primed to respond to the changein telephone line voltage. This “primed” period is typically enabled foronly a few seconds to enhance security and to prevent false triggeringof communication between the BDRs caused as a result of normal telephoneuse.

To initiate communication with the first BDR 2, the second BDR 8 sends asignal along the telephone line 4, which in effect, takes the phone offthe hook/“seizes” the line. This results in a drop in the telephone linevoltage, which is detected by the first BDR, and results in initiationof communication between the first BDR and the second BDR.

In the embodiment described, the second BDR will only attempt to respondto the first BDR provided that it has been enabled by the broadcasterreceiving the appropriate EMM.

The two BDR's communicate with each other using a modulation techniquewhich does not interact with the telephone exchange and which isavailable via the existing BDR modem. For example, Frequency ShiftKeying (FSK) can be used which allows the transfer of digital databetween the BDR's but will not falsely dial the telephone exchange.Alternatively, line current modulation can be used and this has theadvantage that a full modem is not required to be incorporated withinthe second BDR 8.

The second BDR 8 includes a timer built into the software such thatoperation of the BDR is for a limited period of time only. After thelimited period of timer has expired, the timer of the second BDR 8 needsto be reset using an authorisation code provided by the first BDR 2 inorder for BDR 8 to function.

For example, the BDR timer can be set for a period of 72 hours, afterwhich time the BDR will cease to function normally unless the timer isreset.

The authorisation code can be set via the first BDR and can be regularlychanged at the head end of the BDR's software, thereby reducing thelikelihood of the code being deciphered and used to bypass the system.The code can also be sent from the broadcaster to one of the receiversor during a normal telephone dial-up communication.

Normal user telephone usage is not effect by the system of the presentinvention.

Thus it can be seen that the present invention provides communicationbetween at least two broadcast data receivers via connection of thereceivers to the same telephone line to allow operation of at least onethe receivers. Communication between the two receivers only takes placewhen one of the broadcast data receivers detects the presence of theother on the telephone line. The system is secure and cannot be easilybypassed as is the case with conventional systems.

1. A broadcast data receiver system, said system comprising: a firstbroadcast data receiver located at a first location in a premises,receiving video, audio and/or auxiliary digital data broadcast from aremote location via cable, satellite or terrestrial means and processingand displaying said data on a display screen and/or audio data viaspeakers connected thereto; at least a second broadcast data receiverprovided at at least a second location in the same premises as saidfirst broadcast data receiver; said premises being provided with atelephone line and at least two access points to said telephone line;said first and said at least second broadcast data receivers togetherbeing connected to said telephone line in parallel via respective accesspoints; one of said first and second broadcast data receivers being madefunctional to receive broadcast data by a signal received from the otherof said first and second broadcast data receiver via the telephone line;said signal only being transmitted after an authorization code has beencommunicated to at least one of said first and said at least secondbroadcast data receivers from a broadcast head end transmitter, saidauthorization code priming the broadcast data receivers to allowcommunication therebetween via said telephone line for a limited period;and said first and said at least second broadcast data receivers areprovided in a same premise and are registered to the same user, suchthat use of the broadcast data receivers independently in differentpremises is prevented by the requirement for periodic authorization viathe telephone line in said same premise.
 2. A system according to claim1 wherein said telephone line is a functional public switched telephonenetwork line.
 3. A system according to claim 1 wherein said at least oneof said first and said second broadcast data receivers is provided withtimer means having reset capabilities such that the broadcast datareceivers(s) will function for a limited period only following receiptof a signal from the other of said broadcast data receivers. unless thetimer means is reset.
 4. A system according to claim 3 wherein saidtimer means is reset by inputting of an authorization code in saidbroadcast data receiver.
 5. A system according to claim 1 wherein saidauthorization code is changed at regular intervals at said broadcasthead end transmitter.
 6. A system according to claim 1 wherein saidbroadcast head end transmitter enable said first and said at leastsecond broadcast data receivers for a limited period time.
 7. A systemaccording to claim 1 wherein a communication sequence is initiated inone of said first and said at least second broadcast data receiver(s) onreceipt of an enabling signal from said broadcast head end transmitter.8. A system according to claim 1 wherein said first and said at leastsecond broadcast data receivers communicate using frequency shiftkeying.
 9. A system according to claim 1 wherein said first and said atleast second broadcast data receivers communicate using line currentmodulation.
 10. A method of operating a broadcast data system, saidsystem comprising the steps of: a first broadcast data receiver locatedat a first location receiving video, audio and/or auxiliary digital databroadcast from a remote location, at least a second broadcast datareceiver being located at at least a second location wherein said firstand said at least second broadcast data receives are registered to thesame user; said first and at least second broadcast data receivers beinglocated in a same premise and connected to respective access points fora telephone line within the premise to allow communication between thebroadcast data receivers; said communication only being allowed for alimited period after an authorization code has been communicated from abroadcast head end transmitter to at least one of said first and said atleast second broadcast data receivers; said first broadcast datareceiver monitoring the telephone line for change in voltage; at leastsecond broadcast data receiver taking the telephone line off a hook whenoperation of the at least second broadcast data receiver is required;and said first broadcast data receiver detecting a change in thetelephone line status and then initiating communication between saidfirst broadcast data receiver and said at least second broadcast datareceiver, thereby allowing the at least second broadcast data receiverto become operational to receive broadcast data.
 11. A method accordingto claim 10 wherein said first broadcast data receiver communicates anauthorization signal to said second broadcast data receiver to allowsaid second broadcast data receiver to become operational.
 12. A methodaccording to claim 10 wherein said first broadcast data receiver doesnot initiate communication with said at least second broadcast datareceiver until a broadcast head end transmitter has enable both saidfirst and said at least second broadcast data receiver.
 13. A broadcastdata receiver system, said system comprising: a first broadcast datareceiver located at a first location in a premise receiving video, audioand/or auxiliary digital data broadcast from a remote location viacable, satellite or terrestrial means and processing and displaying saiddata on a display screen and/or audio data via speakers connectedthereto; at least a second broadcast data receiver provided at at leasta second location in the same premise as said first broadcast datareceiver; said premise being provided with a telephone line and at leasttwo access points to said telephone line; p1 said first and said atleast second broadcast data receivers being connected together inparallel using said telephone line via respective access points; one ofsaid first and second broadcast data receiver being made functional by asignal received from the other of said first and second broadcast datareceiver via the telephone line; an authorization code beingcommunicated to at least one said first and said at least secondbroadcast data receivers from a broadcast head end transmitter; oncesaid at least one broadcast data receiver receives said authorizationcode, the authorization code is communicated to one or more other saidbroadcast data receivers via said telephone line in the premise; andsaid at least one of said first and said second broadcast data receiversis provided with a timer having reset capabilities such that thebroadcast data receivers(s) will function for a limited period onlyfollowing receipt of a signal from the other of said broadcast datareceivers, unless the timer is reset, the timer being reset by receptionof an authorization code via said telephone line.